package com.source.app.discriminate.train;


import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class BinaryTest {

	public static void main(String[] args) throws IOException {
		BufferedImage bufferedImage = ImageIO.read(new File("img2/1.jpeg"));
		int h = bufferedImage.getHeight();
		int w = bufferedImage.getWidth();
		
		// 灰度化
		int[][] gray = new int[w][h];
		for (int x = 0; x < w; x++) {
			for (int y = 0; y < h; y++) {
				int argb = bufferedImage.getRGB(x, y);
				int r = (argb >> 16) & 0xFF;
				int g = (argb >> 8) & 0xFF;
				int b = (argb >> 0) & 0xFF;
				int grayPixel = (int) ((b * 29 + g * 150 + r * 77 + 128) >> 8); 
				gray[x][y] = grayPixel;
				bufferedImage.setRGB(x, y, grayPixel);
			}
		}
		
		
		// 二值化
		int threshold = ostu(gray, w, h);
		BufferedImage binaryBufferedImage = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_BINARY);
		for (int x = 0; x < w; x++) {
			for (int y = 0; y < h; y++) {
				if (gray[x][y] > threshold) {
					gray[x][y] |= 0x00FFFF;
				} else {
					gray[x][y] &= 0xFF0000;
				}
				binaryBufferedImage.setRGB(x, y, gray[x][y]);
			}
		}
	
		// 矩阵打印
		for (int y = 0; y < h; y++) {
			for (int x = 0; x < w; x++) {
				if (isBlack(binaryBufferedImage.getRGB(x, y))) {
					System.out.print("*");
				} else {
					System.out.print(" ");
				}
			}
			System.out.println();
		}
		
		ImageIO.write(binaryBufferedImage, "jpg", new File("img2/1_2.jpg"));
	}
	
	public static boolean isBlack(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() <= 300) {
			return true;
		}
		return false;
	}
	
	public static boolean isWhite(int colorInt) {
		Color color = new Color(colorInt);
		if (color.getRed() + color.getGreen() + color.getBlue() > 300) {
			return true;
		}
		return false;
	}
	
	public static int isBlackOrWhite(int colorInt) {
		if (getColorBright(colorInt) < 30 || getColorBright(colorInt) > 730) {
		return 1;
		}
		return 0;
	}
	
	public static int getColorBright(int colorInt) {
		Color color = new Color(colorInt);
		return color.getRed() + color.getGreen() + color.getBlue();
	}
	
	public static int ostu(int[][] gray, int w, int h) {
		int[] histData = new int[256];
		// Calculate histogram
		for (int x = 0; x < w; x++) {
			for (int y = 0; y < h; y++) {
				int red = 0xFF & gray[x][y];
				histData[red]++;
			}
		}
	
		// Total number of pixels
		int total = w * h;
		
		float sum = 0;
		for (int t = 0; t < 256; t++)
			sum += t * histData[t];//区域，长*高
		
		float sumB = 0;
		int wB = 0;
		int wF = 0;
		
		float varMax = 0;
		int threshold = 0;
		
		for (int t = 0; t < 256; t++) {
			wB += histData[t]; // Weight Background
			if (wB == 0)
				continue;
			
			wF = total - wB; // Weight Foreground
			if (wF == 0)
				break;
			
			sumB += (float) (t * histData[t]);
			
			float mB = sumB / wB; // Mean Background
			float mF = (sum - sumB) / wF; // Mean Foreground
			
			// Calculate Between Class Variance
			float varBetween = (float) wB * (float) wF * (mB - mF) * (mB - mF);
		
			// Check if new maximum found
			if (varBetween > varMax) {
				varMax = varBetween;
				threshold = t;
			}
		}
		
		return threshold;
	}
}